A 58 year old man presents with chest discomfort following mild to moderate exertion for 4 months. His symptoms resolve completely with rest. He was diagnosed with diabetes 15 years ago, which is well controlled. His smoking history amounts to 30 pack-years. There is no family history of heart disease.
The Troponin-T assay is negative.
The resting ECG appears completely normal.
The patient develops chest pain and horizontal ST segment depressions in leads V1 to V4 at stage II of the stress test (Bruce protocol), following which the test is terminated.
Coronary Angiography shows a 70% to 80% stenosis of the proximal portion of the left anterior descending artery, with a left dominant coronary circulation.